/Engine/Source/Runtime/CoreUObject/Public/UObject/SparseDelegate.h
Removes all sparse delegate binding from the owner for a given object. Returns true if there are still bindings to the delegate.
static bool RemoveAll ( const [UObject](API\Runtime\CoreUObject\UObject\UObject) * DelegateOwner, const [FName](API\Runtime\Core\UObject\FName) DelegateName, const [UObject](API\Runtime\CoreUObject\UObject\UObject) * UserObject )